Atomic absorption spectrometry is a well-known method for quantitating a micro-amount metal contained in a sample at high precision. In atomic absorption spectrometry, a sample is atomized at high temperature, and the atmosphere containing the atomized sample is irradiated with light. The absorption spectrum of the micro-amount metal contained in the sample is quantitated from the corresponding absorption spectrum. In atomic absorption spectrometry, a light source that emits the bright line spectrum of an analysis target element is required. When a plurality of elements are analyzed, the corresponding light sources that emit bright line spectra of the elements are required.
Patent Document 1 discloses a multi-micro hollow cathode light source as a light source that provides bright line spectra of such elements. The light source disclosed in Patent Document 1 has an anode plate, an insulation plate, and a cathode plate made of copper or copper alloy stacked together; a plurality of through-holes penetrating the stacked structure and each having a diameter of 1 cm or less; and metal plates that provide bright line spectra of interest at openings of the through-holes at the cathode plate, whereby the corresponding bright line spectra of a plurality of metal elements are provided. In other words, the light source disclosed in Patent Document 1 is a single-point light source providing a plurality of types of hollow cathode discharge corresponding to the metal elements of interest.